With Blender 2.80 we introduced a more flexible matcap system. One change we did was to multiply the matcap with the base color that was shaded. As matcaps contains diffuse and specular lighting in a single texture this lead to rendering artifacts. Artists were complaining that everything looked to metalic. We now support a separate `diffuse` and `specular` pass for matcaps. `shaded_color = diffuse_light * base_color + specular_light` For matcaps to support this feature they need to be multilayer openexr files with 2 renderpasses (named `diffuse` and `specular`). In the future we can change this to first pass/second pass in stead of this naming convention. Reviewed By: fclem, brecht Differential Revision: https://developer.blender.org/D5335